PICSI is a laboratory technique used in the treatment of in vitro fertilization in order to select the sperm that have intact DNA, that is, the best sperm to be injected into the eggs will be selected. One of the last steps of sperm maturation is the appearance of receptors for hyaluronic acid in the cytoplasmic membrane. Hyaluronic acid is a component present in the egg’s membrane. In this way, these receptors are necessary to adhere the sperm to the egg and, thus, fertilization occurs.
The sperm are placed on a laboratory plate with a substance called hyaluronidase, similar to that found in the outer layer of the eggs. This substance attracts the best quality, mature sperm with normal, healthy DNA that will be isolated and sent to IVF-ICSI. This procedure mimics what occurs naturally in the fallopian tubes at the time of fertilization and reduces the chances of chromosomal abnormalities. However, the fragmentation test (PICSI) assesses the percentage of sperm that have had their DNA fragmented, that is, that are not able to complete the embryo’s DNA. Therefore, the higher the percentage of gametes with fragmented DNA, the greater the probability that the embryo will not develop or implant.
Indications for research on spermatic DNA fragmentation
DNA fragmentation of sperm can be caused by diseases such as varicocele, unhealthy lifestyle habits (external factors), such as obesity, smoking, drug use, high fever, high testicular temperature, pollution, old age or internal factors. as well as, apoptosis and the production of free radicals. Values above 20% decrease the sperm’s ability to fertilize the oocyte (egg) properly and normal fertilization may occur, but with the formation of embryos that show developmental delay, implantation failures, repeated abortions, resulting in in vitro fertilization (IVF).